Avian Flu H5N1 Spread in Animal Populations
Avian flu H5N1 was first documented among some wild and domestic bird populations
in Southeast Asia. As bird migration experts had predicted, wild birds infected
with H5N1 avian flu have now been found on the European continent and, more
recently, in England. It is now predicted that infected birds will likely be
found in the northern regions of the North American continent by Spring 2006.
Infection of the migratory bird populations of North America is likely to follow.
Some domesticated species beyond poultry have been documented to have acquired
avian flu H5N1 infection. In Southeast Asia and elsewhere a number of domestic
cats and some captive tigers were found to have died of H5N1 after having apparently
consumed the uncooked carcasses of H5N1 infected birds. The significance of
species other than birds becoming infected is unclear at this point. Part of
the reasoning for culling infected or possibly infected bird populations is
to limit the number of infections overall, including inter-species dissemination
of H5N1, a near impossibility to prevent in the wild. Some feel that the pathway
to efficient human-to-human transmission may arise from a modification of H5N1
as it passes among other susceptible species.
Should H5N1 infected wild birds be found in the US, it is important to consider
that the US poultry industry differs significantly from that in less well developed
countries of the world. Commercially raised flocks (over 95% of poultry sold)
are raised in isolation from the wild in the US. Even so, enhanced measures
are being implemented to further prevent potential contact between wild birds
and commercial poultry. Beyond that, flock testing and quarantining will likely
become the norm once H5N1 infected wild birds are found in North America. The
CDC and the Department of Agriculture further assure that properly cooked poultry
poses no H5N1 threat to other animals or humans since cooking neutralizes the
virus’ pathogenicity. On the other hand, preventing pets from consuming
uncooked bird carcasses may become a necessary consideration for pet owners.
Human H5N1 Infections
Human infection with H5N1 avian flu remains relatively rare and efficient transmission
from human to human (the remaining key factor for an H5N1 pandemic to potentially
occur among humans) has not been documented.
As of May 12, 2006, the World Health Organization reports 208 cumulative human
H5N1 cases. 115 deaths have been attributed to H5N1 since 2003. Though these
are seemingly small numbers, it should be noted that the number of cases and
fatalities have increased significantly each year since 2003 and that the number
of cases and fatalities already recorded for 2006 (through May 12) indicates
that 2006 will mark a period of further acceleration in the number of human
cases occurring and deaths resulting.
Though the mortality rate among confirmed cases is extremely high (55%), many
investigators feel that the lethality of the actual strain of H5N1 that might
cause a pandemic will likely (and hopefully) be significantly lower than that
noted in the “sporadic” cases so far. That being said, one should
not lose sight of the fact that the fatality rate of the H1N1 “Spanish”
flu of 1918 was about 2.5% and it proved to be a devastating world-wide morbidity
and mortality event. Whether the next pandemic (due to H5N1 or some other flu
virus) will follow the course of a 1918-like scenario or that of a milder pandemic
such as occurred in the 1968 is unknown but the potential degree of social and
economic upheaval will likely be significant either way and appropriate personal
and business related planning still remains a prudent consideration.
Pandemic Risk in the U.S.
Historically, pandemics have occurred every 10–68 years and it has been
over 37 years since the last major pandemic. Though not all virologists feel
that H5N1 will be the next pandemic-causing virus, most government experts feel
that a significant flu pandemic will occur in the not too distant future. Many
feel that a combination of factors surrounding the emergence of H5N1 make it
as likely a causative agent as has been seen in a long while.
Speculation continues as to the likelihood of H5N1 pandemic flu occurring in
the very near future. At least one learned Medical Director has ventured that
the likelihood is about 15% that a pandemic will occur in the next two years,
with the odds for such occurring escalating each year thereafter. Most feel
that any such pandemic will directly affect the US.
Progress on the Vaccine Front
Although a veterinarian vaccine to protect domesticated birds against H5N1 is
available, there remains no human avian flu H5N1 vaccine at this point. Research
is ongoing in a number of centers. A report on one such research effort and
an editorial in the March 30, 2006 New England Journal of Medicine highlighted
some of the bright promise and coincident difficulties of providing reliable
protection from this pathogen. Though major efforts are underway in many labs,
it still appears likely that a vaccine will not be available for human use for
some time to come.
Bottom Line
Considerable uncertainty remains with regard to H5N1. On the other hand, pandemic
flu of significance appears to be an inevitability whether it will be H5N1 or
some other viral pathogenic. At present, the US, state and local governments
continue to work to develop response plans for varying pandemic scenarios as
well as to stockpile medical supplies that may be helpful in treating those
who are exposed to or become ill with H5N1. Much still remains to be done. A
number of insurance companies are actively developing or are modifying business
continuity plans with pandemic flu in mind. We encourage our business associates
to be pro-active rather than reactive on this issue.
Resources for further information
www.pandemicflu.gov
– federal clearinghouse for info on pandemic flu
www.pandemicflu.gov/plan/checklists.html
– preparedness checklists for home and business
www.cdc.gov
– Centers for Disease Control and Prevention website
healthyamericans.org
– AMA flu website for general public – New
www.dhhs.gov/nvpo/pandemics
– Dept of Health and Human Services, National Vaccine Program Office,
lots of interesting information, see FluAid and FluSurge for impact planning
calculators (FluWorkLoss calculator is in development)
Recent articles of possible interest to the Insurance Industry
“Pandemic: Can The Life Insurance Industry Survive The Avian Flu”
by Steven Weisbart, Ph.D., CLU, Insurance Information Institute,
www.iii.org;
January 17, 2006
“Bird Flu – Will It Ruffle the Industry’s Feathers”
By Simone Peakin, ACA, et al; FitchRatings,
www.fitchratings.com
